Seamless pipe or tube mill



Je 22, 1937 v s. FlNDLATER 2,084,331

SEAMLESS PIPE O R TUBE MILL Filed Nov. 2l, 1934 6 Sheets-Sheet l bwefdo:Y STEVE/vso/v F/NDLQTEE,

.Pune 22, 1937. s. FlDL-ATI'ER i 1 2,084,331

- SEAMVLESS PIPE OR TUBE MILL Filed Nov. 21, 1934 6 sheets-sheet 2 ySTEVENSO/v HNDLQTEE;

`une 22, 1937. s, FINDLATER v 2,084,331

SEAMLESS PIPE OP. TUBE MILL Filed Nov. 2l, 1954 6 Sheets-Sheet 3lwenfo': STEVE/VSON HNQLQTEE,

June 22, 1937. s F'INDLATER 2,084,331

SEAMLESS PIPE OR TU BE MILL Filed Nov. 21, 1954 e sheets-sheet 41jwed'o: STEVENSON /F//VDQQT/ffe,

June 22, 1937. s. FINDLATER 2,084,331

SEAMLES'S PIPE OF` TUBE MILL Filed Nov. .21, 1934 e sheets-sheet 5 IJune22, 1937. s, FINDLATER 2,084,331

SEAMLESS PIPE OP. TUBE MILL Filed NOV. 21, 1934 6 Sheets-Sheet 6Patented June 22, 1937 iP/MEN ori-loa 2,084,331 sEAmEss faire oa TUBEMns.

Stevenson Findlater, McKeesport, Pa., assigner to National 4TubeCompany, a corporation of New Jersey Application November 21, 1934,Serial No. 754,169

4 Claims.

This invention relates to improvements in seamless pipe or tube mills,and more particularly to means `for automatically compensating for theexpansion of the mandrel bar.

In the manufacture of seamless pipes and tubes, considerable diflicultyhas been encountered in maintaining constant the distance between thesurfaces of the various rolls of the mill and the surfaces of themandrel plug, such as is commonly used in piercing, expanding,elongating, reducing, etc., operations. While this condition can beattributed somewhat to the expansion of the rolls and mandrel plug, itis largely due to the expansion of the mandrel barl supporting the plugin the roll pass. That is to say, as the rolls and mandrel plug of themill acquire heat from the work-piece being processed they will, ofcourse, expand, causing their surfaces to become closer to one another.As the mandrel bar becomes hotter, acquiring heat from the work-piecebeing processed, it will increase in length and accordingly move thesurfaces of the mandrel plug nearer to the rolls of the mill. Thismoving together of the various metal working surfaces of the mill causesthe wall thickness of the work-piece being processed to vary, due to amore substantial reduction in the wall of the work-piece when themandrel bar, rolls and mandrel plug are hot than would be the case werethey cold.

The temperature of a seamless pipe or tube mill is usually no higher atthe end of a long period of operation than it was at the beginning. Thisis for the reason that the mill is started without cooling water on therolls and heated billets passed therethrough until the rolls acquire adesired temperature. At this time the rolls are sprayed with Water inorder that theftemperature will not rise greatly beyond that desired. Inthis manner the general temperature of the mill is maintained asdesired; but as each highlyv heated billet, or work-piece, moves throughit, the temperature of the mill elements is temporarily raised. Thistemporary rise in temperature causes a correspondingly temporary expan-December 29, 1934, Serial No. 759,804, I have' disclosed apparatus whichis inmany respects similar to that disclosed herein. This copendingapplication is, however, concerned with makJ lng a tubular work-piecewhich is tapered in both inside diameter and wall thickness.

One object of the present invention is to provide novel andautomatically actuated means for` compensating to exactness theexpansion of the mandrel bar and rolls of the mill, and maintain- -ingconstant the distance between the surfaces of the various rolls of themill and the surfaces of the mandrel plug, resulting in elimination ofvariations from the desired wall thickness of the work-piece. A

Another object of the invention is to provide novel and automaticallyactuated mechanism, operating under a heavy thrust, for slowlywithdrawing the mandrel bar of a seamless tube mill in exact ratio tothe expansion o'f the mandrel bar and of the rolls in the mill,resulting in a constantly maintained distance between the various metalworking surfaces, together with automatically actuated mechanism forrapidly returning the mandrel plug to its initial position.

A further object is to regulate the relative positions of the mandrelplug to the various metal working rolls, even when the mill is cold, inaccordance with the temperature of the workpiece, and thus compensatefor differences in resistance to metal displacement caused byintroducing metal of varying temperature into the mill.

A still further object is to provide novel apparatus of the classdescribed which can be installed on existing mills with butl littlemodification and expense.

These and further objects of the invention will appear after referringto the drawings, in which:

Figure 1 is a fragmentary plan of a conventional pipe or tube mill.

Figure 2 is a fragmentary plan of the apparatus of the invention.

Figure 3 is a sectional view on the line III-III of Figure 2.

Figure 4- is a view onthe line ure 3.

Figures 5 and 6 are electrical circuits for operating the variouselements of the invention.

Referring to Figure- 1 of the drawings, there is disclosed aconventional seamless pipe or tube mill of the well known Stiefel type,comprising a pair of cone-shaped metal Aworking rolls A between whichthere is disposed a mandrel plug B.

IV--IV of Fig- In this gure of the drawings one of the cone- .4 issecured to the carriage 3 in any suitable manner as, for example, by acoupling 4* on the extension 3* of a thrust bearing located immediatelyat the rear thereof.

A support l is pivoted to the frame 2, as at 5*,

r and provided with a horizontauy disposed shaft 3 adjacent the uppersurface of the mandrel bar carriage 3. -A pair of links 3. is secured tothe shaft t and is adapted, by suitable mechanism, to move the support Babove the pivot 3*.

A motor 3 is secured to the frame 2 and provided with the usualmotorshaft 3* and coupling III, for connecting theI same to a shaft I I*of a gear reduction mechanism generally indicated at II. The gearreduction II is provided with another shaft Ilb and a coupling I2 forconnection .to a shaft I3 which is iournaledin a bearing I4.l

A magneticclutch I3 is disposed adjacent the bearing I4 for clutching-inashaft I3. A worm ,I1 is mounted on the shaft I3 for rotating a wormgear 24. The worin gear 24 is provided with a suitably journaledelongated sleeve portion 24",

yon which it is mounted. The elongated sleeve portion 24* is internallyscrew-threaded for engagement with a screw 2t, which is secured to oneof the links 3 by a pin 2V. The other end of the shaft I3 is providedwith acoupling It to which there is secured a shaft I3on which there ismounted a worm 23. The shaft I3 is secured at its other end to the shaft23* oi' a motor 23, by means of a coupling 2I.

The worm 23 is adapted to cooperate with a worm gear 23 which is mountedon a suitably Journaled elongated sleeve 23*. 'I'he elongated sleeve 23*is internallyscrew-threaded to receive a screw21, which is secured tothe free end of the'other of thelinks 3 by a pin 21..

A magnetic b e 23 is provided for the motor 23. A latch 1 is secured tothe horizontal shaft 3 and is adapted to make contact on its outer endwith a wear-plate 3'I which is secured to the mandrel bar carriage 3.

,The horizontal shaft 3 and latch 1, which is secured thereto, areadapted to be partially rotated by means ofa rod 1*, which is secured tothe shaft 3 at one of its ends in a suitable manner, and to the pistonof an air cylinder 1* at its other end.

'A suitable and conventional electrical wiring circuit including apyrometer device, relays. and preferably also pushbuttons, is providedfor the motors 3 and 23, the magnetic clutch device Il and the magneticbrake 23 for the motor 423.

'Ihe rotation of the motor 3 is automatically compensated fordiil'erences in theresistance to metal displacement caused byintroducing metal of varying temperatures into the rolls. The operationis such that the variations in temperature of the work-piece beingprocessed, as measured by photoelectric, optional radiation or otherpyrometer, will be transmitted to the motor 3 insuchmannerastoincreaseorretardtherotation thereof, thereby varying therate at which the compensator operates.

In operation, upon the entry of a pipe or tube described. As beforestated, the'rate at which the motor operates is controlled throughsuitable resistance, modied by the action of the pyrometer. gear'reduction 'I I and shaft I 3, through the magn etic clutch I5, istransmitted to the worm I1, coupling I3 and, by means of shaft I3, theworm 23. 'I'he worms I1 and 23 will rotate the worm gears 24 and 23, andtheir respective sleeves 24* and 26*. The action will cause the screws2l and 21 to draw the links 3 and attached support 5 backward, or awayfrom the mill, and accordingly permit the same movement of the mandrelbar 4 and the plug B on `theother end thereof. A tendency of the plug,mandrel bar and mandrel bar carriage to move backwardly will, of course,be caused by the action of the work-piece in the mill. This motion willbe slowly permitted, as determined by the'suitable.l resistancedescribed, until the work-piece has passed through the mill.

'I'he rotation of the shaft I6, which is transmitted to the shaft I3 bymeans of the coupling I8, will cause the shaft 23* of the motor 23 torotate idly, when the motor 3 is energized to withdraw the mandrel barcarriage.

After the work-piece has. passed throughthe mill, the mandrel barcarriage and attached mandrel bar must be quickly returned in order toposition the mandrel plug (not shown) in its initial position in themill, before the next tube or work-pieceds introduced into the rolls A.

The operator attending the device, or a suitable relay, momentarily-energizes the magnetic brake 23 for the motor 23. 'I'his operation atthe same time instantaneously deenergizes the magnetic clutch I3 anddisengages the motor 3. The motor 23 is then actuated to reverse thedirection of rotation of the worms 23 and l1 to rapidly return thesupport 3 to position preparatory to-rolling the next work-piece. -Atthe proper and predetermined position, the action of the motor 23 isarrested by' a suitable limit switch, which also applies the brake 23for the motor 23.

As before stated, the motor 23 will rotate when bar carriage but, uponthe return straks of the carriage, when the motor 23 is enerdned, themagnetic clutch Il ,is ,deenergized preventing rotation of the gearreduction, generally indicated at II, and the'motor 3.

Referring to Figures 5 and 6 of the drawings, I have disclosed in sdiagram one form of electrical control which'will function to operatethe elements of the invention in the manner previously described. Inthis diagram the numerals 33 and 3I designate suitable power linescarrying normal voltage; such as 220 volts.

In order to satisfactorily control the operation of the motor 3, a wire33 is connected between the power lines 33 and 3|, and includes astarting switch 34 and a coil 33.` A line 33 connects the line 33,between the power line 3| and the starting switch 34, to the line 33,between the starting switch 34 and the coil 33.

'rms` une n includes a manually opera' stopping switch 33 and a pair ofcontacts 3l* which are operated by the coil 3l. A line 33 connects thelline 33, between thel contacts 33* and the line 33, with the line 33between the coil 3l and the power line 3|. This line includes a coil 43and a pair of contacts 3l", the latter valso ...une

'I'he motion transmitted by the motor 3,l

=the action of the motor 3 withdraws the mandrel 83, and a pair ofcontacts 80, the latter being.

being operated by the coil 35. A line 4| is connected to the line 36,-between the contacts 35e and the line 33, and to the line 38 between thecoil 40 and the contacts 35". This line` 6| has included in its circuita pair of coils 62 and 43 and -an auxiliary magnetic switch M.

The motor 8 is connected between the power lines 38 and 3| by a line 8which includes two pairs of contacts, as at 82 and 63a, which areoperated by the coils d2 and 83, respectively. This line 66 alsoincludes a pair of contacts d8 between the power line 30 and the motor8, and a pair of contacts B8 between the contacts d2 and 83 and thepower line 3|. The contacts dllB and 30h are operated by the coil iiiand likewise the auxiliary contacts dt The photoelectric pyrometerdevice, which is generally indicated at X, is connected by a line d8with a series of relays d8, 58, 5|, 52, 53 and 54. These relays form apart of'a field rheostat 55 which eects an automatic speed adjustmentfor the motor 9. Each of these relays is adjusted to trip at a denitetemperature. This eld rheostat is connected between the power lines 38and 3| by a line 56. This line 56 has included therein, between thepower line 30 and the eld rheostat 55, the shunt eld for the motor 9,which is designated at 9a, and a hand-operated rheostat 51.

Referring to Figure 5 of the drawings, it is to be noted that the motorfor rotating the usual metal working rolls is diagrammatically shown at58, being connected by a line 59 between suitable power lines 80 and 8|.While one motor 58 is'illustrated in the drawings and may be employed todrive both of the metal working rolls through the medium of suitablegearing (not shown), the invention also contemplates the driving of eachroll with an individual motor..

higher voltage than that furnished through the power lines 30 and 8|;as, for instance, 600 volts. A shunt is included in the line 5d betweenthe power line B8 and the motor 58. A pair of lines 68 and $1 connectthe shunt 85 with a load relay $8. The magnetic clutch i5 which iscarried on the shaft i8 is connected between the power lines 38 and 3|by a line 18, which has included therein two pairs of contacts, as at68B and 68h, one on either side of the magnetic clutch. The magneticbrake 28 is connected by a line il with the power Alines 38 and 3| andincludes in its circuit two pairs of contacts, as at t5 and 85|. A linei3 is connected to the line 18 between the power line 38, and thecontacts 88B, and to the line 1| between the contacts 85 and themagnetic brake 28.' Thisv line 13 includes a pair of contacts 68. Asimilar line 'B4 is connected to the line 18 between the power line 3iandthe lline 38 and the starting switch 18 with the line 11 betweenthestarting switch 18 and the limit switch 18. This line 8| includes astopping switch operated by the coil 88.

A line 84 connects the line 8| between the contacts 80B and limit switchi9 with the line 11 between the coil 88 and the power line 3|. The line84 has included in its circuit a pair of coils 85 and a pair of contacts80h, the latter being operated by the coil 88. A line 81 is connected tothe line 8| between the contacts 88 and the limit switch 19, and to theline 84 between the coils 85 and the contacts 80h. cludes in its circuita pair of coils 88, 89 and'an auxiliary switch 85e, the latter beingoperated by the coils 85.

, y The coils 85 of the line 84, in addition to operating the auxiliarymagnetic switch 85e, also operate the contacts 85e and 85h in the line1|.

The motor 23 is connected between the power lines 30 and 3| by a line 98which has included therein al pair of contacts 88a and 89a which areoperated by the coils 88 and 8S, respectively, of the line 81, A pair ofcontacts are disposed in the line 98 between the motor 22 and the powerline 38 as indicated at 85; while asimilar pair of contacts 85d aredisposed in the line 90 between the power linev 3| and the contacts 88Band 89a.

A line 8i is connected between the power lines 3@ and 3i and includesthe shunt eld for the motor 23, which is designated at 23a, and ahandoperated irheostat 93.

The energization of the load relay 88 closes the contacts 68 and 68 inthe line 1G, and the contacts 88c and 88d in the lines 13 and 18, re-

spectively.

The limit switch 19 is arranged in such manner as to be opened by themovement of the This line 81 inmandrel bar carriage 3 to its originalposition in the mill, prior to the processing of a work-piece.

In operation: The operator of the mill closes the starting switch 38 forthe motor 8, thus energizing the coil 35 (which is maintained by itscontacts 358), thus closing the contacts 35B and 85 and energizing thecoil 48 to close the contacts dit? and dill. The closing of thesecontacts and the contacts of the auxiliary switch M, which they eiect,starts the motor 8 whichwill attain a speed of rotatie-n which ispredetermined by the setting of the hand-operated rheostat 51. Theclosing of the contacts of the auxiliary switch it energides the coils 2and '43, thus closing the 25 and csa.

contacts As the work-piece (not shown) enters the mill, the power`required bythe motor 58 in driving the metal working rolls passesthrough the shunt 65. This causes a voltage drop across the shunt, andenergizes the load relay 68, which causes the closing of the contacts68, 58h, 88 and 68d. The closing of these contacts energizes themagnetic clutch i5, and the magnetic brake 28. The

accompanying coupling of the clutch and the releaseof the brakemechanically connects the motor 8, which is running, as previouslymentioned. 'I'he motor 8 withdraws the'g mandrel bar carriage 3 of themill at a speed which' is predetermined by the setting of thehand-operated rnetat t1.

, The photoelectric pyrometer device, which is generally designated atX, is set for a predetere mined temperature indication. and if thetemperature of the work-piece as it passes the point upon which it istrained, is either above or below this indication, the relays 49 through54, inclusive, are individually, and progressively excited and caused tofunction. The functioning of these relays will include, or delete,sections of the field rheostat 55 to increase, or decrease, the speed ofoperation of 'the motor 8. It will thus be seen that the rate ofwithdrawal of the mandrel bar vcarriage 3 is indirect proportion to thetemperatue of the work-piece being processed in the mill. That is tosay, the size of the pass will remainA constant regardless of variationsresulting from expansion of the mandrel plug and rolls, which is, inturn, due to temperature changes. 'I'hese changes in temperature takeplace upon the entry into the mill of each highly heated work-piece.

'Ihe power required by the motor, or motors,

\ V5i! which drives the metal working rolls of the approach zero, and inconsequence thereof the deenergization of the load relay 58. The,Ideenergization of this load relay opens the contacts 48", 68h, Sac and68d, to deenergize the magnetic clutch l5 and the magnetic brake 28.This last operationv uncouples the clutch and applies the brake to stopthe motor 9.

,After the operator has removed the work-piece from the mill from theusual discharge trough (not shown) and returns the mandrel bar to theusual position, he operates the starting switch 18 for the motor 23. Theoperation of the starting switch I8 for the motor 23 energizes the coil80 (which is maintained by one of its contacts 80.) and closes thecontacts 80* and 80h; thus energizing the coils 85. The energization ofthel coils 85 closes the contacts 85, 85, 85 and 85d and the contacts ofi drel bar carriage 3 to its original position in the mill, which isvpredetermined by the location of the limit swith 18, the latter openingwhen this position is reached. The opening ofthis limit switchdeenergizes the coil 88, thus opening the contacts .88* and 88, therebystopping -the operation of the motor 28 and eiecting. the application ofthe magnetic brake 28. all by the opening of the various contacts 85,A85h, 85 and 85, and the contacts of the auxiliary `switch 85, which iscaused by the deenergization of the coils 8l.

'Ihe equipment' is now ready for another cycle of operation, which iseiected by the entry of a second work-piece between the rolls of themill which are driven by the motor 58. 'Ihis effects a second "voltagedrop" across the shunt 85, which energizes the load relay 88, thusrepeating the operation previously described.

While I have shown and described certain speciilcl embodiments of myinvention, it will be un- ,derstood-that I do not wish to be limitedexactly thereto, since various modiiications may be made withoutdeparting from the scope of my invention, as deiinedf'by the followingclaims.

I claim:

1. A seamless pipe or tube mill comprising in 'combination at least onepower actuated metal -working roll, a roll for coacting with said rst ofsaid mandrel plug is adjusted with respect to said rolls, meansresponsive to the temperature of said pipe or tube for modifying the.rate of 'speed of said last named means, and means for returning saidcarriage to its initial position.

2. A seamless pipe or tube mill comprising, in combination, at least onepower actuated metal working roll, a roll for` coacting with said ilrstnamed roll, a movable carriage, a mandrel bar connected to and extendingfrom said movable carriage, a mandrel plug carried on the extended endof said mandrel bar, said mandrel plug being adapted for disposalintermediate said rolls, a support adjacent said carriage, means on saidsupport-for making contact with said carriage, means for moving saidsupport away from said rolls while a pipe or, tube is being acted uponby said rolls and said mandrel plug, said last named means permittingsaid carriage to likewise move away from said rolls, whereby theposition of` said mandrel plug is adjusted with respect to said rolls,means responsive to the temperature of said pipe or tube for modifyingthe rate of speed of said last named means, and means for returning saidsupport and said carriage `to their initial positions.

3. A seamless pipe or tube mill comprising, inA

combination, at least one power actuated'metal working roll, a roll forcoacting with said rst named roll, a mandrel bar, a mandrel plug carriedby said mandrel bar, said mandrel plug being adapted for disposalintermediate said rolls, means for withdrawing said mandrel plug fromsaid rolls to maintain a desired relationship between the surfaces ofsaid mandrel plug and said rolls while a pipe or tube is being actedupon thereby, means responsive to the temperature of said pipe ortubefor controlling the speed of operation of said withdrawing means,and-means for returning the withdrawn mandrel plug to its initialposition.

`4. A seamless pipe or tube mill comprising,`in combination. at leastone power actuated metal working roll,a roll for coacting with saidiirst for expansion and-maintain substantially constants soy thedistance between the surfaces of said mandrel plug and said rolls whilea pipe or tube is being acted upon thereby, means responsive to thetemperature of said pipe or tube for controlling the speed of. operationof said withdrawing means, and means for returning the withdrawn mandrelplug to its initial position. L

N FINDLATER.

